1. Field of the Invention
The present invention relates to a heat and cooling treatment apparatus and a substrate processing system.
2. Description of the Related Art
In the semiconductor device fabrication processes, a photolithography process is performed for a front face of a substrate, for example, a semiconductor wafer (hereinafter, referred to as xe2x80x9cwaferxe2x80x9d) and the like. In this photolithography process, a series of treatments is performed, in which a predetermined pattern is exposed after a resist solution is applied to the front face of the wafer, and thereafter developing treatment is performed.
In the coating and developing treatments, after the resist coating, exposure, developing treatments as above, treatments of heating the wafer are performed as required, and thereafter treatments of cooling the wafer which has increased in temperature are performed. Further, the coating and developing system for performing the coating and developing treatments is provided with various kinds of treatment units for performing these treatments individually, and the wafer is carried into/out of each unit by a main carrier unit having an arm and the like.
The heat treatment is usually performed in a heat treatment unit. As shown in FIG. 6, a heat treatment unit 100 is provided with a heating table 101 and a cooling arm 102. The heating table 101 mounts the wafer W thereon by means of support pins 103, 103, and 103 which are provided on the top face of the heating table 101, and performs heat treatment for the wafer W by heat generated by a heater 104 embedded in the heating table 101. On the other hand, the cooling arm 102 forms a substantially square flat plate shape and is configured to be movable forward and backward with respect to the heating table 101 by means of a drive mechanism not shown and to receive the wafer W which has been subjected to the heat treatment from the heating table 101. When receiving the wafer, the cooling arm 102 does not contact the support pins 103 by virtue of slits 105, 105, and 106 which are formed in the cooling arm 102. Furthermore, a circulation passage 107 is formed inside the cooling arm 102. The circulation passage 107 is connected to a constant temperature water supply source (not shown) to circulate a constant temperature water with a temperature of, for example, 23xc2x0 C. Therefore, the cooling arm 102 allows the wafer W to wait which has been subjected to the heat treatment until it is carried out of the unit to perform simple pre-cooling treatment, thereby causing the wafer W to decrease in temperature to some extent.
In the cooling treatment unit, a cooling table is provided. The cooling table mounts thereon the wafer W which has been subjected to the pre-cooling treatment, performs precise cooling treatment by a Peltier element embedded in the cooling table to thereby bring the wafer to a predetermined temperature (for example, 23xc2x0 C.).
However, in the conventional heat treatment unit 100, when the wafer W is mounted on the cooling arm 102, portions of the rear face of the wafer corresponding to the slits 105, 105, and 106 are not in contact with the cooling arm 102. Therefore, the non-contact portions of the rear face of the wafer and portions of the front face of the wafer opposing to the portions of the rear face of the wafer are often low in temperature reduction as compared with other portions of the front and rear faces of the wafer. Further, when the cooling arm 102 is not large enough to mount the wafer W thereon, there exist portions which lie off the cooling arm 102, and the lying-off portions of the front and rear faces of the wafer are also low in temperature reduction. Moreover, it happens that the timing of carrying the wafer W out of the heat treatment unit 100 is delayed, prolonging the waiting period of the wafer in the cooling arm 102. For this reason, there are some cases where cooling effects on the wafers W by the cooling arm 102 are different. Also ununiformity in in-plane temperature distribution and unevenness in cooling effect, which are almost negligible before, have room for improvement in order to realize more precise fabrication technology in response to progression of micromachining technology.
When the chemically amplified resist is used, in post-exposure bake (PEB) which is heat treatment after exposure, it is necessary to promptly shift the wafer W, after the pre-cooling treatment similarly by the cooling arm 102, to precise cooling treatment to prevent deformation and deterioration in reproduction of a pattern due to amplification reaction of acid. However, since conventionally the heat treatment unit 100 and the cooling treatment unit are provided separately, it takes time to carry the wafer W out of the heat treatment unit 100 into the cooling treatment unit. In these days when patterns become minuter, the moving period of the wafer W between the units, which has been insignificant conventionally, is susceptible to causing deformation and deterioration in reproduction of the patterns, and therefore there is room for improvement also on the point of the moving period of the wafer W.
The present invention is made in the above viewpoints, and its object is to provide new treatment apparatus and substrate processing system capable of making in-plane temperature distribution of a substrate and cooling effects uniform and shifting to precise cooling treatment more promptly than before.
The present invention is an apparatus for performing heat and cooling treatments for a substrate includes a heating table for mounting the substrate thereon to perform the heat treatment for the substrate, a cooling table for mounting the substrate thereon to perform the cooling treatment for the substrate, a waiting table for allowing the substrate to wait, a carrying mechanism for carrying the substrate between the heating table, the cooling table, and the waiting table, and airflow formation means for forming airflow in a space in which the heating table, the cooling table, and the waiting table are arranged.
In the heat and cooling treatment apparatus of the present invention, the cooling table has a cooling adjusting element, for example, a Peltier element or the like inside thereof so as to perform the precise cooling treatment by cooling operation of this cooling adjusting element. The heat and cooling treatment apparatus as above carries the substrate to the heating table and the cooling table in sequence by means of the carrying mechanism to perform heat and cooling treatments successively. Since the substrate is mounted on the cooling table during the cooling treatment, the cooling treatment can be performed for the entire substrate uniformly. Thus, the apparatus, in which the precise cooling treatment is performed without delay, is excellent in time management on the heat and cooling treatments. Therefore, it is possible to make in-plane temperature distribution of the substrate uniform and to make the cooling effects on substrates the same even when the cooling treatment is performed for a plurality of substrates. Further, the apparatus can conduct the shift to the precise cooling treatment more promptly than before, thereby preventing deformation and deterioration in reproduction of a pattern. Consequently, yields can be improved.
Moreover, a substrate which is an object to be processed next is allowed to wait on the waiting table in advance and substrates are carried to the heating table and the cooling table one after another, whereby heat and cooling treatments can be performed for a plurality of substrates successively. Therefore, throughput can be improved.
It is preferable that a heat treatment case for housing the heating table is provided in the heat and cooling treatment apparatus of the present invention. Further, it is preferable that a cooling treatment case for housing the cooling table is provided. In that case, the heat treatment case can prevent the thermal influence by the heating table to diffuse thereabout, and the cooling treatment case can intercept the thermal influence by the heating table exerting on the cooling table. Accordingly, the heating table and the cooling table can carry out intended treatments even if they are arranged in the same apparatus.
Further, it is more preferable that a heat insulation material for intercepting radiation heat of the heating table is provided.
Furthermore, it is preferable that the airflow formation means comprises an exhaust port formed on the heating table side, and an exhaust mechanism for exhausting through the exhaust port an atmosphere in a space in which the heating table, the cooling table, and the waiting table are arranged. In the case where the exhaust mechanism is, for example, an exhaust fan, operation of the exhaust fan can form airflow which flows from the cooling table side to the heating table side in the space. The airflow as above can prevent a hot atmosphere produced by the heating table from flowing to the cooling table side. Further, since the airflow flows from the cooling table side to the heating table side, it comes to contain a cool air, thereby instantly cooling the substrate which has been subjected to the heat treatment while carrying the substrate from the heating table to the cooling table.
Moreover, the present invention is a system for processing a substrate includes the heat and cooling treatment apparatus as above, and a solution treatment apparatus for supplying a treatment solution to the substrate to perform a predetermined treatment for the substrate, the cooling table being disposed on the solution treatment apparatus side, in the heat and cooling treatment apparatus.
In the substrate processing system, the cooling table is disposed on the side of the solution treatment apparatus, in the heat and cooling treatment apparatus. Therefore, the cooling table is interposed between the solution treatment apparatus and the heating table, with the result that the thermal influence by the heating table does not exert on the solution treatment apparatus. As a result, a predetermined solution treatment can be preferably performed for the substrate.